55742220 has 72 divisors (see below), whose sum is σ = 172304496. Its totient is φ = 14581632.

The previous prime is 55742189. The next prime is 55742249. The reversal of 55742220 is 2224755.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6619 + ... + 12461.

It is an arithmetic number, because the mean of its divisors is an integer number (2393118).

Almost surely, 2^55742220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55742220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86152248).

55742220 is an abundant number, since it is smaller than the sum of its proper divisors (116562276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55742220 is a wasteful number, since it uses less digits than its factorization.

55742220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5911 (or 5906 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 27.

The square root of 55742220 is about 7466.0712560221. The cubic root of 55742220 is about 381.9982913404.

Adding to 55742220 its reverse (2224755), we get a palindrome (57966975).

The spelling of 55742220 in words is "fifty-five million, seven hundred forty-two thousand, two hundred twenty".